It is recognised that LED light sources are theoretically more efficient than incandescent light bulbs and solutions have been proposed to construct LED luminaires as for example taught in U.S. Pat. No. 6,609,804. A luminaire usually refers to a complete lighting unit which contains one or more electric lighting sources and associated reflectors, refractors, housing, and such support for those items as necessary with the parts designed to distribute the light, to position and protect the lighting sources and to connect the lighting sources to a power supply. LED's are usually operated with a nominal 20 mA forward direct current and 3.5V forward voltage. The voltage drop across a LED is substantially independent of the current through the diode. Typical LED luminaires are usually constructed from an array of discrete LED's which operate together to provide a desired lumen value and are incorporated within a light fixture having a low voltage DC converter within the fixture to convert the AC mains supply to a low voltage DC supply for powering the LED array. The AC to DC converters are bulky, making it a challenge to fabricate a LED lighting fixture to replace, for example, an existing Edison type incandescent light bulb fixture.
Furthermore, the optical performance of LED's are affected by a rise in temperature This thermal problem has reduced the feasibility of LEDs as viable lighting sources and has limited the wide spread adoption of LEDs as commercial and residential lighting sources.
Thus, there still remains a need for an LED light source that can easily replace standard residential and commercial light fixtures but which uses less bulky power control systems and runs cooler.